Universal hinge for articulated joints



Aug. 2, 1949. G. B. ROBINSON UNIVERSAL HINGE FOR ARTICULATED JOINTSFiled Nov. 29, 1947 MN uw MN@ NNNN u r2.7 7 f, f

INVENTOR Patented Aug. 2, 1949 UNIVERSALHINGE Fon ARTICULATED `JoIN'rsjY v George B. Robinson, Vallejo, Calif. Application November 29, 1947,Serial No. 788,792

3 Claims.

- This invention relates to improvements in hinges and connectionsforarticulated members particularly for the knee, ankle, wrist and elbowjoints of artificial limbs, and provides a connection which allowstwisting movement in connection with hinging movement of membersrelative to each other, and therefore has a distinct advantage overconventional hinge joints.

With conventional hinge joints, the parts can move or swing only aboutthe axis of the pintle, allowing no twisting movement, and artificiallimbs so hinged lack the life-like movement so much desired and which isessential to proper mechanical functioning of the various parts.

With my hinge, the parts can swing as freely as with the conventionalpintle hinge while also permitting limited twisting movement, when thehinges are placed on opposite sides of a joint, and when one hinge isused axially between two joints and the joints vare connected by aball-A and-socket connection, such asin a wrist or ankle, normaltwisting of one part relative to the other is possible.

Unlike other spring hinges, inthis hinge the spring can be eitherclosedor restrained such as ,o'ne which is compressed to closedf position by aflexible tie, and with the spring encased in a flexible or elasticsleeve, the sleeve and spring both having their terminal ends anchoredin the hinge straps, which are provided with divided heads forconvenience in manufacture and assembly.

In describing the invention reference will be made to the accompanyingdrawings, in which:

Fig. 1 shows an articial leg with my invention applied thereto.

Fig. 2 is a top plan view of Fig. 1.

Fig. 3 is an enlarged side view of the invention with the strap headsshown in section to show the spring and sleeve connections.

Fig. 4 is a greatly enlarged longitudinal section through the inventionwith the projecting ends of the straps broken away.

Fig. 5 is an enlarged top plan view of one of the heads showing themethod of assembly.

Fig. 6 is an enlarged section through one of the heads.

The invention includes a pair of straps Ill and II which are providedwith suitable means for attaching to the respective members to bejoined, such as the socket I2 to the artificial leg I3, and which extendto the end I4 of the anchoring means or heads I5 and I6.

The heads I5 and I6 each consist of the end portion of the strap II andtwo plates I1 and pitchv the spring is compressed to an almost' closedposition by a head 25 slipped over the other end of the cable and withthe cable drawn taut, the head is fixed on the cable, thus rmly holdingthe spring in the substantially closed position with just enough freedomto permit bending or hinge action.

A sleeve 26 of flexible, slightly elastic material is slipped over thespring, and this sleeve is preferably provided with a bead 2l at eachend to lock the ends in the heads I5 and I6, a suitable material for thesleeve being a vinyl-resin plastic which is very iiexib'le and slightlyelastic, though live rubber can also be used. Slight elasticity isessential to allow for the bending" action, and synthetic rubber is moresuitable than natural'rubber V because of its limited elasticity. Thisbead 21 permits'the sleeve to be placed and maintained under tension toprevent bulging or cooking of the spring.

To assemble the hinge, one end of the assembly of cable, spring andsleeve is placed in the opening made in the strap Il, with the end ofthe spring located in the threaded passage, with the ends of the sleevelocated in the counterbore 20, the plates I1 and I8 are placed inposition on the strap, the screws I9 inserted and drawn up tight, whichlocks the end of the spring securely in the threaded bore and the sleeveend in the plain bore 2U. The other end of the hinge unit is thensecured in the other strap in the same way.

As previously outlined, with the spring not tightly closed, a certainamount of spring action is provided between the connected parts toprovide a life-like feel and appearance, and the parts can be relativelytwisted to a limited degree in either direction, and there will be nochance for any clicking of the washers 24 and 25 against the walls ofthe bore.

However, the spring can be wound tightly closed as shown, with slightclearance provided between the ends of the spring and the washers asindicated at 28, under which conditions the 3 hinging action will bemore firm and direct and will be limited to that clearance.

The sleeve 23 should not be too elastic as it is intended to maintainthe shape of the spring and prevent bulging or cocking, yet must besufficiently elastic to permit the hinge action. It also serves as aguard for the spring. The edges 29 are arcuately formed to preventcutting or breaking of the sleeve'. yv I i, Y' K Thus a'V hinge isprovided which" is universali hinging in any direction, and which allowslim--5 ited twisting of parts and which is economicali and easy tomanufacture and a ssernble;= and` which upon application to anartiiicial limb will" assure positive action coupled with resiliency andfreedom of movement, resultingiinmoelifee' like action and control ofartificial limbs;

I claim:

1. A hinge for an articial limb compisiri'g a* pair of relatively rigidstraps for attachment to the respective parts of theflimbandconne'ctedfto-A g-ether-` by a substantiallyV closedspr-inghavingrestraining-tmeans limiting. expansion" of the spring tothat necessaryA for hinge action fiexureand# comprising a cable threadedthrough'thespii'ng and-having a headat each end and having saidl springunder compression' toy a' substantiail'y closedposition, and WithAthe'endsof the springiixed'in the endsof tlierespectiverstraps;` aflex-y ible;v slightly resilient sleevef encompassing said? springtofunctionas a'- guardand to prevent' bulging. or buckling of the springand'havingit'sf respective ends: hired in the said Vends' o`f therespectivestraps; said ends of.' said straps-include ing.: each-a 'platefor eachiac'e and kwith'the'plates and strapsecured together to* fo'rm'a clamping' head and having a threaded bore" to secure? the` endof saidspring and'a counterbore'tosecure the end-ofthe sleeve, andfbeingsecuredtogether with said spring and sleeve inplace-for positively ser curing;the springY and-sleeve thereini 2; Af universal hingecomprising; a'-substan-` tially closed spirali springy having a' cablepassingtherethrough and terminating in a" head'at'eachff end to cooperate withtheends ofthespring-ahd limiting. the spring to a predetermined degreefo'fI exure, and' a, exible sleeveencompassing; the;` spring. throughoutthe greater portion: cfAV its* length,- and anchoring meansv for the;respective 2l ends of the spring and of the sleeve; said spring beingcompressed to a substantially closed condition by said cable betweensaid heads, to provide a predetermined degree of resiliency for directthrust and necessary expansion of one side of the spring for the hingeaction; said flexible sleeve being formed of elastic material andclosely fitting said spring and having the respective endstheeifanehbfedin said1 archrig'ne'ans under terisibn'wfighuy^c1osenihe=spring while permitting exure, and holding said springagainst blging or cooking; said anchoring means comprisingf'for each endof the spring, a strap and aL plate secured on each side thereof to forman anchoring head and having a threaded bore to lb'ck tleverid of thespring and a counterbore for securing-the end ofthe sleeve, said sleevehaving a length less than th'e length of the spring to perni'itspaateanchoring.

3. In a hinge including a closed spiral spring anda-tension'memberwithin'said spring for liiniting'exure and'a'sleeve encompassingthegreat; er-` portiono the length of sa'id'spring; means for securing theend' of the spring comprising three plateslandmeansifor securing' thethree plates-'t0A` getr'reif` and:i havingv jointly a' threaded bore andacounterbore common' to the: three plates; with said threaddbore havinga pitch-of threadequal tothe pitch of the'springto securefthe end ofthespring; andfsaidcouiiterbor'e having` a diameter'- sligltlyf less than"the Outside diameter o'f the sleeve' tof secure the sleeve, and with.the'` endl of the spring and-1 ef the sleevefplaced in-positio'nsin oneplate:y and 1 clamped by th'eotlier' twoplate'sto Drvdepositve'alichlfng thereof'.

GERGE B5 ROBINSON.

' are of this pater-115;'

UNITED' STATES" PATENTS

